[trac613] catch exceptions by (const) reference.

src/lib/config/ccsession.cc

@@ -170,10 +170,10 @@ ModuleCCSession::readModuleSpecification(const std::string& filename) {
 
     try {
         module_spec = moduleSpecFromFile(file, true);
-    } catch (JSONError pe) {
+    } catch (const JSONError& pe) {
         cout << "Error parsing module specification file: " << pe.what() << endl;
         exit(1);
-    } catch (ModuleSpecError dde) {
+    } catch (const ModuleSpecError& dde) {
         cout << "Error reading module specification file: " << dde.what() << endl;
         exit(1);
     }

src/lib/config/module_spec.cc

@@ -121,7 +121,7 @@ void
 check_module_specification(ConstElementPtr def) {
     try {
         check_data_specification(def);
-    } catch (TypeError te) {
+    } catch (const TypeError& te) {
         throw ModuleSpecError(te.what());
     }
 }

src/lib/config/tests/module_spec_unittests.cc

@@ -36,7 +36,7 @@ moduleSpecError(const std::string& file,
     EXPECT_THROW(moduleSpecFromFile(specfile(file)), ModuleSpecError);
     try {
         ModuleSpec dd = moduleSpecFromFile(specfile(file));
-    } catch (ModuleSpecError dde) {
+    } catch (const ModuleSpecError& dde) {
         std::string ddew = dde.what();
         EXPECT_EQ(error1 + error2 + error3, ddew);
     }